Industry Segments - Corporate Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
General and administrative expense	$ 34,926	$ 34,446	$ 105,498	$ 98,866
Depreciation, amortization, and accretion	30,867	29,460	93,312	84,880
Interest expense, net	18,146	18,894	55,054	52,246
Fair Value Adjustment of Warrants			(1,035)	22
Other (income) expense, net	(690)	619	(1,014)	7,203
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	9,079	12,852	35,954	46,041
Corporate Overhead [Member]
Segment Reporting Information [Line Items]
General and administrative expense	12,573	13,037	39,012	37,506
Depreciation, amortization, and accretion	167	172	507	487
Interest expense, net	5,495	5,268	16,533	14,152
Fair Value Adjustment of Warrants	78	(179)	(1,035)	22
Other (income) expense, net	(382)	1,333	(96)	1,703
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 17,931	$ 19,631	$ 54,921	$ 53,870